The course of asthma in young adults: a population-based nine-year follow-up on asthma remission and control

Abstract

Background: Only few longitudinal studies on the course of asthma among adults have been carried out.

Objective: The aim of the present prospective study, carried out between 2000 and 2009 in Italy, is to assess asthma remission and control in adults with asthma, as well as their determinants.

Methods: All the subjects with current asthma (21-47 years) identified in 2000 in the Italian Study on Asthma in Young Adults in 6 Italian centres were followed up. Asthma remission was assessed at follow-up in 2008-2009 (n = 214), asthma control at baseline and follow-up. Asthma remission and control were related to potential determinants by a binomial logistic and a multinomial logistic model. Separate models for remission were used for men and women.

Results: The estimate of the proportion of subjects who were in remission was 29.7% (95%CI: 14.4%;44.9%). Men who were not under control at baseline had a very low probability of being in remission at follow-up (OR = 0.06; 95%CI:0.01;0.33) when compared to women (OR = 0.40; 95%CI:0.17;0.94). The estimates of the proportion of subjects who were under control, partial control or who were not under control in our sample were 26.3% (95%CI: 21.2;31.3%), 51.6% (95%CI: 44.6;58.7%) and 22.1% (95%CI: 16.6;27.6%), respectively. Female gender, increasing age, the presence of chronic cough and phlegm and partial or absent asthma control at baseline increased the risk of uncontrolled asthma at follow-up.

Conclusion: Asthma remission was achieved in nearly 1/3 of the subjects with active asthma in the Italian adult population, whereas the proportion of the subjects with controlled asthma among the remaining subjects was still low.

Figure 1. Distribution of GINA-based asthma control at follow-up according to GINA-based asthma control measured at baseline.

The percentage of subjects in each category of GINA-based asthma control at follow up is reported inside histograms. The numbers of subjects with controlled, partially controlled and uncontrolled asthma at baseline are different from those reported in the result section due to missing data on control at follow-up.

Figure 2. Distribution of treatment step* according to GINA classification in subjects with controlled asthma, partially controlled asthma and uncontrolled asthma, at follow-up.

* STEP 1: As needed short-acting β₂-agonist; STEP 2: Sustained release theophylline OR Leukotriene modifier OR Low-dose Inhaled Corticosteroids (ICS); STEP 3: Low-dose ICS plus long-acting β₂-agonist OR Low-dose ICS plus leukotriene modifier OR Low-dose ICS plus sustained release theophylline OR Medium or high dose ICS; STEP 4: Medium or high dose ICS plus long-acting β₂-agonist OR Medium or high dose ICS plus leukotriene modifier OR Medium or high dose ICS plus sustained release theophylline; STEP 5: Oral corticosteroids or Anti-IgE treatment.